JP6859708B2 - How to manufacture semiconductor devices - Google Patents

Description

The present invention relates to a method of manufacturing a semiconductor device.

Conventionally, a wire bonding method using a fine metal wire such as a gold wire has been widely applied to connect a semiconductor chip and a substrate, but in order to meet the demands for high functionality, high integration, high speed, etc. for semiconductor devices, A flip-chip connection method (FC connection method) in which a conductive protrusion called a bump is formed on a semiconductor chip or a substrate and is directly connected between the semiconductor chip and the substrate is becoming widespread.

Flip-chip connection methods include a method of metal bonding using solder, tin, gold, silver, copper, etc., a method of applying ultrasonic vibration to metal bonding, a method of maintaining mechanical contact by the shrinkage force of resin, etc. However, from the viewpoint of reliability of the connecting portion, a method of metal bonding using solder, tin, gold, silver, copper or the like is common.

For example, in the connection between a semiconductor chip and a substrate, a COB (Chip On Board) type connection method, which is widely used in BGA (Ball Grid Array), CSP (Chip Size Package), etc., is also a flip chip connection method. .. The flip-chip connection method is also widely used in a COC (Chip On Chip) type connection method in which bumps or wirings are formed on a semiconductor chip and the semiconductor chips are connected to each other (see, for example, Patent Document 1).

Area array type semiconductor packages used for CPUs, MPUs, etc. are strongly required to have high functionality. Specific requirements include an increase in the size of the chip, an increase in the number of pins (bumps, wiring), a high density of pitches and gaps, and the like.

For packages that are strongly required to be further miniaturized, thinned, and highly functional, chip stack type packages in which the above-mentioned connection methods are laminated and multi-staged, POP (Package On Package), TSV (Through Silicon Via), etc. are also available. It is beginning to spread widely. Since the package can be made smaller by arranging it in a three-dimensional shape instead of a flat shape, these technologies are also effective in improving semiconductor performance, reducing noise, reducing the mounting area, and saving power, and are effective for next-generation semiconductor wiring technology. It is attracting attention as.

From the viewpoint of improving productivity, COW (Chip On Wafer), which manufactures a semiconductor package by crimping (connecting) a semiconductor chip onto a wafer, and then crimping (connecting) wafers to each other to form a semiconductor package. WOW (Wafer On Wafer) for producing the above is also attracting attention. Further, from the same viewpoint, a batch connection method in which a plurality of chips are aligned on a wafer or a map substrate and temporarily crimped, and then the plurality of chips are collectively heat-treated to secure a connection is also attracting attention. ..

Japanese Unexamined Patent Publication No. 2008-294382

In the highly productive batch connection method described above, the chip and the chip or substrate are temporarily crimped to each other via a semiconductor adhesive, and then the metal at the connection portion between the chip and the chip or substrate is melted. Secure the connection. However, if the semiconductor adhesive is rapidly exposed to a high temperature equal to or higher than the melting point of the metal at the connection portion after the temporary crimping, voids may occur and poor connection may occur. In addition, when voids are generated, reliability (for example, reflow resistance) may decrease.

A main object of the present invention is a semiconductor device that sufficiently suppresses the generation of voids, has a good connection, and has excellent reflow resistance in the manufacture of a semiconductor device, which includes connecting the connecting portions by metal bonding. To get.

One aspect of the present invention includes a semiconductor chip, a substrate or another semiconductor chip, and a curable adhesive layer interposed between them, and each of the semiconductor chip, the substrate, and the other semiconductor chip has a connection portion. Manufactures semiconductor devices that have, at least part of the connection is made of a metal material, and the connection of the semiconductor chip is electrically connected to the substrate or the connection of another semiconductor chip by metal bonding. Regarding how to do it. The method has a semiconductor chip, a semiconductor wafer including a substrate, another semiconductor chip, or a portion corresponding to another semiconductor chip, and a curable adhesive layer arranged between them, and the semiconductor chip. The laminate in which the connection portion of the above and the connection portion of the substrate or another semiconductor chip are arranged to face each other is heated and pressurized by sandwiching the laminate between a pair of pressing members facing each other, whereby the substrate and other semiconductors are attached to the semiconductor chip. A step of crimping a chip or a semiconductor wafer, a step of advancing the curing reaction of a curable adhesive layer, and a step of electrically connecting a semiconductor chip connection portion and a substrate or another semiconductor chip connection portion by metal bonding. And are prepared in this order. At least one of the pair of pressing members is the melting point of the metal material forming the connection part of the semiconductor chip when heating and pressurizing the laminate, and the metal forming the connection part of the substrate or other semiconductor chips. It is heated to a temperature lower than the melting point of the material. In the step of advancing the curing reaction of the curable adhesive layer, the laminate is the melting point of the metal material forming the connection part of the semiconductor chip and the metal material forming the connection part of the substrate or other semiconductor chips. It is heated to a temperature lower than the melting point of the above, whereby the curing reaction of the curable adhesive layer is allowed to proceed until the curing reaction rate of the curable adhesive layer becomes 80% or more. In the step of electrically connecting the connection part of the semiconductor chip and the connection part of the substrate or another semiconductor chip by metal bonding, the laminate is the melting point of the metal material forming the connection part of the semiconductor chip, or the substrate or the substrate. It is heated to a temperature equal to or higher than the melting point of at least one of the melting points of the metal material forming the connection portion of the other semiconductor chip.

According to the method for manufacturing the above-mentioned semiconductor device, after the substrate, another semiconductor chip or the semiconductor wafer is pressure-bonded to the semiconductor chip, the curing reaction of the curable adhesive layer is performed so that the curing reaction rate of the curable adhesive layer is 80% or more. By advancing until the above, the generation of voids can be sufficiently suppressed when the connection portion of the semiconductor chip and the connection portion of the substrate or another semiconductor chip are subsequently electrically connected by metal bonding. As a result, it is possible to manufacture a semiconductor device having a good connection and excellent reflow resistance.

The melt viscosity of the curable adhesive layer may be 10,000 Pa · s or less at the temperature at which the pressing member is heated.

The curable adhesive layer may be a layer containing a thermosetting resin having a molecular weight of 10,000 or less and a thermosetting resin composition containing the curing agent.

The thermosetting resin composition may further contain a polymer component having a weight average molecular weight of 10,000 or more. The weight average molecular weight of the polymer component may be 30,000 or more. The glass transition temperature of the polymer component may be 100 ° C. or lower.

The curable adhesive layer may be a layer formed by a film-like adhesive.

According to the present invention, with respect to the manufacture of a semiconductor device including connecting the connection portions by metal bonding, the generation of voids is sufficiently suppressed, and a semiconductor device having a good connection and excellent reflow resistance is obtained. be able to.

It is a process drawing which shows one Embodiment of the process of crimping a substrate to a semiconductor chip. It is a process drawing which shows one Embodiment of the step of advancing the curing reaction of a curable adhesive layer. It is a process drawing which shows one Embodiment of the process of electrically connecting the connection part of a semiconductor chip and the connection part of a substrate by metal bonding. It is a schematic cross-sectional view which shows one Embodiment of a semiconductor device. It is a schematic cross-sectional view which shows the other embodiment of the semiconductor device. It is a schematic cross-sectional view which shows the other embodiment of the semiconductor device.

Hereinafter, preferred embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments. The upper and lower limits of the numerical range described in the present specification can be arbitrarily combined. The numerical values described in the examples can also be used as the upper limit value or the lower limit value of the numerical range. As used herein, the term "(meth) acrylic" means acrylic or the corresponding methacrylic.

<Manufacturing method of semiconductor devices>
The method for manufacturing a semiconductor device according to the present embodiment includes a step (crimping step) of crimping a semiconductor chip with a substrate, another semiconductor chip, or a semiconductor wafer with a pressing member. FIG. 1 is a process diagram showing an embodiment of a process of crimping a substrate to a semiconductor chip.

First, as shown in FIG. 1A, the semiconductor chip main body 10 and the semiconductor chip 1 having the bump 30 as the connecting portion are attached to the substrate main body 20 and the substrate 2 having the wiring 16 as the connecting portion. The curable adhesive layer 40 is placed between them and superposed to form the laminated body 3. After being formed by dicing the semiconductor wafer, the semiconductor chip 1 is picked up and conveyed onto the substrate 2, and is aligned so that the bump 30 as a connecting portion and the wiring 16 are arranged so as to face each other. The laminate 3 is formed on the stage 42 of the pressing device 43 having the crimping head 41 and the stage 42 as a pair of pressing members arranged so as to face each other. The bump 30 is provided on the wiring 15 provided on the semiconductor chip main body 10. The wiring 16 of the substrate 2 is provided at a predetermined position on the substrate main body 20. At least a part of the bump 30 and at least a part of the wiring 16 are each made of a metal material. For example, the bump 30 and the wiring 16 may each have a surface formed of a metal material.

The curable adhesive layer 40 may be a layer formed by attaching a film-like adhesive to the substrate 2. The film-like adhesive can be attached by a heat press, roll laminating, vacuum laminating or the like. The supply area and thickness of the film-like adhesive are appropriately set according to the size of the semiconductor chip 1 or the substrate 2, the height of the connecting portion, and the like. The film-like adhesive may be attached to the semiconductor chip 1. The semiconductor chip 1 to which the film-like adhesive is attached may be produced by attaching the film-like adhesive to the semiconductor wafer and then dicing the semiconductor wafer to individualize the semiconductor wafer.

Subsequently, as shown in FIG. 1B, the laminate 3 is heated and pressurized by being sandwiched between the stage 42 as a pressing member and the crimping head 41, whereby the substrate 2 is crimped to the semiconductor chip 1. .. In the case of the embodiment of FIG. 1, the crimping head 41 is arranged on the semiconductor chip 1 side of the laminated body 3, and the stage 42 is arranged on the substrate 2 side of the laminated body 3. The crimping may be performed so that the connection portion of the semiconductor chip 1 and the connection portion of the substrate 2 are in contact with each other. This facilitates the formation of metal joints between the connecting portions in the subsequent connecting step, and can reduce the biting of the curable adhesive layer between the connecting portions, further improving the connectivity.

When at least one of the stage 42 and the crimping head 41 heats and pressurizes the laminate 3 for crimping, the melting point of the metal material forming the surface of the bump 30 as the connection portion of the semiconductor chip 1 and the substrate. It is heated to a temperature lower than the melting point of the metal material forming the surface of the wiring 16 as the connection portion of 2.

If the heat of the pressing member after the substrate 2 is crimped to the semiconductor chip 1 is transferred to the collet and the temperature of the collet itself rises, a problem occurs when the semiconductor chip is picked up next, and the productivity tends to decrease. In a semiconductor chip on which a curable adhesive layer is formed (a semiconductor chip to which a film-like adhesive is attached), the temperature of the curable adhesive layer rises due to the heat of the collet, and the viscosity of the curable adhesive layer develops. Then, the curable adhesive layer tends to adhere to the collet, and the productivity tends to decrease. In addition, even with a semiconductor chip on which a curable adhesive layer is not formed, when the collet becomes hot, heat is transferred to the dicing tape via the collet when picking up the semiconductor chip that has been separated from the dicing tape. Pickup performance is reduced and productivity is likely to be reduced.

In the step of crimping the substrate 2 to the semiconductor chip 1, it is preferable that the pressing member has a low temperature so that heat is not transferred to the semiconductor chip or the like when the semiconductor chip is picked up. During heating and pressurization for crimping, the pressing member may be heated to such a high temperature that the fluidity of the curable adhesive layer is increased so that voids during entrainment can be eliminated. In order to shorten the cooling time, the difference between the temperature of the pressing member when picking up the semiconductor chip and the temperature of the pressing member when crimping may be small. This temperature difference may be 100 ° C. or lower, or 60 ° C. or lower. This temperature difference may be constant. When the temperature difference is 100 ° C. or less, the cooling time of the pressing member is shortened, and the productivity tends to be further improved.

The temperature of the pressing member may be lower than the reaction initiation temperature of the curable adhesive layer. The reaction start temperature is based on the reaction of the curable adhesive layer under the conditions of a sample amount of 10 mg, a heating rate of 10 ° C./min, and a measurement atmosphere: air or nitrogen using DSC (DSC-Pyirs1 manufactured by PerkinElmer). On-set temperature when heat generation is measured.

From the above viewpoint, the temperature of the stage 42 or the crimping head 41 may be, for example, 0 ° C. or higher and 130 ° C. or lower while picking up the semiconductor chip. Further, the temperature of the stage 42 or the crimping head 41 may be, for example, 50 ° C. or higher and 130 ° C. or lower while heating and pressurizing the laminate 3 for crimping, and 110 ° C. from the viewpoint of improving productivity. Below, or may be 90 ° C. or lower.

At a temperature T (the temperature of the pressing member during heating and pressurizing the laminate) at which the pressing member is heated for crimping, the melt viscosity of the curable adhesive layer is, for example, 10,000 Pa · s or less, or 8,000 Pa · s. It may be as follows. This makes it possible to more effectively suppress the generation of voids and poor connection. Here, the "melt viscosity" is a measuring jig (MCR301, manufactured by Anton Paar Japan Co., Ltd.) under the conditions of a sample thickness of 400 μm, a heating rate of 10 ° C./min, and a frequency of 1 Hz. It refers to the viscosity of the curable adhesive layer in a molten state at a temperature T when measured using a disposable plate (diameter 8 mm) and a disposable sample dish).

The temperature T at which the pressing member is heated for crimping may be a temperature equal to or lower than the reaction start temperature of the curable adhesive layer, the viscosity of the curable adhesive layer is the lowest, and the resin easily flows. However, if the viscosity is too low, the resin may crawl up the side surface of the chip and adhere to the pressing member, which may reduce the productivity. Therefore, in the crimping step, the melt viscosity of the curable adhesive layer may be 1000 Pa · s or more at the temperature T at which the pressing member is heated for crimping.

The load for crimping is, for example, 0. per pin (1 bump) of the semiconductor chip from the viewpoint of eliminating voids between the semiconductor chips or between the semiconductor chips and the substrate and sufficiently contacting the respective connection portions with each other. It may be 009 to 0.2N.

The crimping time may be set to a short time from the viewpoint of improving productivity. The crimping time may be, for example, 5 seconds or less, 3 seconds or less, or 2 seconds or less.

As the pressing device, a crimping machine such as a flip chip bonder can be used.

In the crimping step, a plurality of chips may be crimped.

In stack crimping, which is often seen in TSV-structured packages, a plurality of chips are three-dimensionally crimped. In this case as well, a plurality of semiconductor chips may be stacked one by one and crimped, and then the plurality of chips may be collectively advanced to a subsequent process.

The method for manufacturing a semiconductor device according to the present embodiment is a step of crimping a semiconductor chip with a substrate, another semiconductor chip or a semiconductor wafer to obtain a laminate, and then advancing the curing reaction of the curable adhesive layer ( It has a curing process). The curing of the curable adhesive layer may be performed by, for example, thermosetting. In the following, the case of thermosetting will be described as an example. FIG. 2 is a process diagram showing an embodiment of a step of advancing the curing reaction of the curable adhesive layer.

As shown in FIG. 2, by heating the crimped laminate 3 in the heating furnace 60, the curable adhesive layer 40 is cured until the curing reaction rate of the curable adhesive layer 40 becomes 80% or more. Proceed with the reaction. A plurality of laminates may be heated in one heating furnace 60 to collectively proceed with the curing reaction of the curable adhesive layer in the plurality of laminates.

The curing reaction rate of the curable adhesive layer is a state in which the curing reaction rate of the curable adhesive layer before being crimped in the crimping step is regarded as 0%, and the reaction heat due to the curing reaction is not observed in the differential scanning calorimetry. When the curing reaction rate of the curable adhesive layer is regarded as 100%, it means the rate at which the calorific value due to the curing reaction is reduced from the calorific value due to the curing reaction when the curing reaction rate is 0%. The curing reaction rate was 30 to 300 ° C. at a heating rate of 20 ° C./min using DSC (DSC-7 type manufactured by PerkinElmer) for 10 mg of the untreated and heat-treated curable adhesive layer placed in an aluminum pan. It can be obtained by measuring the differential scanning calorimetry in the temperature range of. For example, in the differential scanning calorimetry, the calorific value ΔH (J / g) due to the curing reaction of the untreated sample is set to “ΔH1”, and the calorific value ΔH (J / g) due to the curing reaction of the sample after heat treatment on the hot plate is performed. Is "ΔH2", and the curing reaction rate can be calculated by the following formula.
Curing reaction rate (%) = (ΔH1-ΔH2) / ΔH1 × 100

The gas in the heating furnace 60 in the curing step is determined from the melting point of the metal material forming the connection portion of the semiconductor chip 1 and the melting point of the metal material forming the connection portion of the substrate 2 when the laminate is heated. Is also heated to a low temperature.

When the curable adhesive layer is heat-cured, the temperature of the gas in the heating furnace 60 in the curing step is set to a temperature at which the curing reaction of the curable adhesive layer proceeds while the laminate is heated. The temperature of the gas in the heating furnace 60 may be, for example, 130 ° C. or higher, or 200 ° C. or lower, or 180 ° C. or lower, from the viewpoint of suppressing voids and improving connectivity. The pressure in the heating furnace 60 is not particularly limited, but may be atmospheric pressure.

The temperature of the gas in the heating furnace 60 in the curing step may be higher than the reaction start temperature of the curable adhesive layer while heating the laminate. By accelerating the curing of the curable adhesive layer, void suppression and connectivity can be further improved.

The temperature of the gas in the heating furnace 60 in the curing step may be constant during the curing step or may be changed in two or more steps. For example, the temperature of the first step is set to a relatively low temperature (for example, lower than the reaction start temperature of the curable adhesive layer), and the temperature of the second step is set to a relatively high temperature (for example, the reaction of the curable adhesive layer). It may be set to a temperature higher than the starting temperature). In this case, the time required for the curing step can be shortened while suppressing the generation of voids, so that the productivity is likely to be improved. The temperature of the first step may be, for example, 50 to 180 ° C. or 50 to 130 ° C. The temperature of the second step may be, for example, 130 to 300 ° C.

In the heating furnace 60 in the curing step, the laminated body may be heated in a state where a weight is placed on the laminated body or the laminated body is clipped. As a result, warpage and poor connection caused by the difference in thermal expansion between the semiconductor chip and the substrate and between the semiconductor chip and the curable adhesive layer can be further suppressed.

As the heating furnace in the curing step, a reflow furnace, an oven, or the like can be used. Alternatively, the laminate may be heated on a hot plate. In this case, the temperature of the hot plate can be set to the same temperature as the gas in the heating furnace. Further, the laminated body may be heated by using the same pressing device as in the crimping step. In this case, the temperature of the pressing member can be set to the same temperature as the gas in the heating furnace.

In the method for manufacturing a semiconductor device according to the present embodiment, after the curing reaction of the curable adhesive layer is allowed to proceed, the connection portion of the semiconductor chip and the connection portion of the substrate or another semiconductor chip are electrically connected by metal bonding. The process (connection process) is provided. FIG. 3 is a process diagram showing an embodiment of a process of electrically connecting a connection portion of a semiconductor chip and a connection portion of a substrate by metal bonding.

As shown in FIG. 3, the bump 30 of the semiconductor chip 1 and the wiring 16 of the substrate 2 are heated by heating the laminate 3 after the curing reaction of the curable adhesive layer 40 has proceeded in the heating furnace 60. And are electrically connected by metal bonding. A plurality of laminated bodies may be heated in one heating furnace 60 to collectively connect the plurality of laminated bodies.

The gas in the heating furnace 60 in the connection step is the melting point of the metal material forming the connection portion of the semiconductor chip 1 or the melting point of the metal material forming the connection portion of the substrate 2 when the laminate is heated. It is heated to a temperature equal to or higher than the melting point of at least one of them.

The temperature of the gas in the heating furnace 60 in the connecting step may be 230 ° C. or higher and 330 ° C. or lower when the metal material of the connecting portion contains solder while heating the laminate. When the temperature of the gas in the heating furnace 60 is 230 ° C. or higher, the solder at the connection portion is likely to melt and a sufficient metal bond is easily formed. When the temperature of the gas in the heating furnace 60 is 330 ° C. or lower, voids are less likely to occur, and solder scattering can be further suppressed. The pressure in the heating furnace 60 is not particularly limited, but may be atmospheric pressure.

The temperature of the gas in the heating furnace 60 in the connection step may be higher than the reaction start temperature of the curable adhesive layer while heating the laminate. By accelerating the curing of the curable adhesive layer during the heating step, void suppression and connectivity can be further improved.

In the heating furnace 60 in the connecting step, the laminated body may be heated in a state where a weight is placed on the laminated body or the laminated body is clipped. As a result, warpage and poor connection caused by the difference in thermal expansion between the semiconductor chip and the substrate and between the semiconductor chip and the curable adhesive layer can be further suppressed.

As the heating furnace in the connection step, a reflow furnace, an oven, or the like can be used. Alternatively, the laminate may be heated on a hot plate. In this case, the temperature of the hot plate can be set to the same temperature as the gas in the heating furnace. Further, the laminated body may be heated by using the same pressing device as in the crimping step. In this case, the temperature of the pressing member can be set to the same temperature as the gas in the heating furnace.

In the embodiments of FIGS. 1, 2 and 3, an example of a step of crimping a semiconductor chip and a substrate is shown, but a method of manufacturing a semiconductor device may include a step of crimping semiconductor chips to each other. Good. Instead of the semiconductor chip 1, a semiconductor wafer before dicing, which includes a plurality of portions corresponding to the semiconductor chip 1, may be used. The semiconductor chips are pressed against each other while being heated at a temperature equal to or higher than the melting point of the bump to connect the semiconductor chips, and the gap between the semiconductor chips is filled with a film-like adhesive so that the connection portion is sealed. When the metal material of the connecting portion contains solder, the semiconductor chip may be heated so that the temperature of the connecting portion (solder portion) is 230 ° C. or higher or 250 ° C. or higher. The connection load depends on the number of bumps, but is set in consideration of absorption of bump height variation and control of the bump deformation amount. The connection time may be set to a short time from the viewpoint of improving productivity. A metal joint may be formed at the connection while melting the solder to remove the oxide film and surface impurities.

The crimping step and the curing step may be performed using the same device, and these steps may be interlocked (continuous). The curing step and the connecting step may be performed using the same device, and these steps may be interlocked (continuous). From the viewpoint of improving productivity, the crimping process is performed using a crimping machine such as a flip chip bonder, and the curing process and the connecting process are interlocked and performed using a reflow furnace, a heating furnace such as an oven, or a hot plate. May be good.

The steps from the pick-up of the semiconductor chip (supplying to the pressing device via the collet) and the alignment to the crimping step and the steps from the curing step to the connecting step may be performed by using separate devices. As a result, the cooling time can be shortened, the cooling step can be omitted, and the productivity can be improved.

The method for manufacturing a semiconductor device according to the present embodiment further includes a step of sealing the laminate (sealing step, molding step) between the crimping step and the curing step, or between the curing step and the connecting step. You may have. As a result, warpage and poor connection caused by the subsequent heat treatment can be further suppressed.

<Semiconductor device>
The semiconductor device obtained by the method for manufacturing the semiconductor device according to the present embodiment will be described. The connection portion in the semiconductor device according to the present embodiment may be either a metal bond between the bump and the wiring or a metal bond between the bump and the bump. In the semiconductor device according to the present embodiment, for example, a flip-chip connection that obtains an electrical connection via a curable adhesive layer can be used.

FIG. 4 is a schematic cross-sectional view showing an embodiment of a semiconductor device (COB type connection mode of a semiconductor chip and a substrate). The semiconductor device 100 shown in FIG. 4A includes a semiconductor chip 1, a substrate (wiring circuit board) 2, and a curable adhesive layer 40 interposed between them. In the case of the semiconductor device 100, the semiconductor chip 1 includes a semiconductor chip main body 10, a wiring 15 arranged on the surface of the semiconductor chip main body 10 on the substrate 2 side, and a bump 30 as a connection portion arranged on the wiring 15. Has. The substrate 2 has a substrate main body 20 and wiring 16 as a connection portion arranged on the surface of the substrate main body 20 on the semiconductor chip 1 side. The bump 30 of the semiconductor chip 1 and the wiring 16 of the substrate 2 are electrically connected by metal bonding. The semiconductor chip 1 and the substrate 2 are flip-chip connected by the wiring 16 and the bump 30. The wirings 15 and 16 and the bumps 30 are shielded from the external environment by being sealed by the curable adhesive layer 40.

The semiconductor device 200 shown in FIG. 4B includes a semiconductor chip 1, a substrate 2, and a curable adhesive layer 40 interposed between them. In the case of the semiconductor device 200, the semiconductor chip 1 has bumps 32 arranged on the surface of the semiconductor chip 1 on the substrate 2 side as a connecting portion. The substrate 2 has bumps 33 arranged on the surface of the substrate 2 on the semiconductor chip 1 side as a connecting portion. The bump 32 of the semiconductor chip 1 and the bump 33 of the substrate 2 are electrically connected by metal bonding. The semiconductor chip 1 and the substrate 2 are flip-chip connected by bumps 32 and 33. The bumps 32 and 33 are shielded from the external environment by being sealed by the curable adhesive layer 40.

FIG. 5 is a schematic cross-sectional view showing another embodiment of the semiconductor device (COC type connection mode between semiconductor chips). The configuration of the semiconductor device 300 shown in FIG. 5A is the same as that of the semiconductor device 100 except that the two semiconductor chips 1 are flip-chip connected via the wiring 15 and the bump 30. The configuration of the semiconductor device 400 shown in FIG. 5B is the same as that of the semiconductor device 200, except that the two semiconductor chips 1 are flip-chip connected via the bumps 32.

In FIGS. 4 and 5, the connection portion of the wiring 15, bump 32, etc. may be a metal film (for example, gold-plated) called a pad or a post electrode (for example, a copper pillar). For example, in FIG. 5B, in the embodiment in which one semiconductor chip has a copper pillar and a connection bump (for example, solder: tin-silver) as a connection portion and the other semiconductor chip has gold plating as a connection portion. When the connection reaches a temperature higher than the melting point of the solder, which has the lowest melting point among the metal materials of the connection, the solder melts and a metal bond is formed between the connections, and the electrical connection between the connections is established. It will be possible.

The semiconductor chip main body 10 is not particularly limited, and various semiconductors such as elemental semiconductors composed of elements of the same type such as silicon and germanium, and compound semiconductors such as gallium arsenide and indium phosphorus can be used.

The substrate 2 is not particularly limited as long as it is a wiring circuit board, and does not require a metal layer formed on the surface of an insulating substrate containing glass epoxy, polyimide, polyester, ceramic, epoxy, bismaleimide triazine and the like as main components. A circuit board on which wiring (wiring pattern) is formed by etching and removing the parts, a circuit board on which wiring (wiring pattern) is formed by metal plating or the like on the surface of the insulating substrate, and a conductive substance on the surface of the insulating substrate. A circuit board or the like on which wiring (wiring pattern) is formed by printing can be used.

The materials of the connecting parts such as the wirings 15 and 16, bumps 30, bumps 32 and 33 (conductive protrusions) are mainly composed of gold, silver, copper and solder (main components are, for example, tin-silver, tin-). Lead, tin-bismuth, tin-copper, tin-silver-copper), tin, nickel and the like are used and may be composed of only a single component or may be composed of a plurality of components. The connecting portion may have a structure in which these metals are laminated. Of the metal materials, copper and solder are relatively inexpensive. From the viewpoint of improving connection reliability and suppressing warpage, the connection portion may contain solder.

The main components of the pad are gold, silver, copper, solder (main components are, for example, tin-silver, tin-lead, tin-bismuth, tin-copper, tin-silver-copper), tin, nickel. Etc. may be used and may be composed of only a single component, or may be composed of a plurality of components. The pad may have a structure in which these metals are laminated. From the viewpoint of connection reliability, the pad may contain gold or solder.

The surfaces of the wirings 15 and 16 (wiring patterns) are mainly composed of gold, silver, copper, solder (main components are, for example, tin-silver, tin-lead, tin-bismuth, tin-copper), tin, nickel and the like. A metal layer as a component may be formed. This metal layer may be composed of only a single component, or may be composed of a plurality of components. The metal layer may have a structure in which a plurality of metal layers are laminated. The metal layer may contain relatively inexpensive copper or solder. From the viewpoint of improving connection reliability and suppressing warpage, the metal layer may contain solder.

The semiconductor devices (packages) as shown in FIGS. 4 or 5 are laminated, and gold, silver, copper, and solder (main components are, for example, tin-silver, tin-lead, tin-bismuth, tin-copper, tin). -Silver-copper), tin, nickel, etc. may be electrically connected. The metal for connection may be relatively inexpensive copper or solder. For example, as seen in TSV technology, a curable adhesive layer may be flip-chip connected or laminated between semiconductor chips to form holes penetrating the semiconductor chips and connected to electrodes on a patterned surface.

FIG. 6 is a schematic cross-sectional view showing another embodiment of the semiconductor device (semiconductor chip laminated type mode (TSV)). In the semiconductor device 500 shown in FIG. 6, the wiring 15 formed on the interposer main body 50 as a substrate is connected to the bump 30 of the semiconductor chip 1, so that the semiconductor chip 1 and the interposer 5 are flip-chip connected. ing. A curable adhesive layer 40 is interposed between the semiconductor chip 1 and the interposer 5. The semiconductor chip 1 is repeatedly laminated on the surface of the semiconductor chip 1 on the side opposite to the interposer 5 via the wiring 15, the bump 30, and the curable adhesive layer 40. The wiring 15 on the pattern surface on the front and back of the semiconductor chip 1 is connected to each other by a through electrode 34 filled in a hole penetrating the inside of the semiconductor chip main body 10. As the material of the through electrode 34, copper, aluminum, or the like can be used.

With such TSV technology, it is possible to acquire a signal from the back surface of a semiconductor chip that is not normally used. Further, since the through electrode 34 is passed vertically through the semiconductor chip 1, the distance between the opposing semiconductor chips 1 and between the semiconductor chip 1 and the interposer 5 can be shortened, and flexible connection is possible. In such TSV technology, the curable adhesive layer according to the present embodiment can be applied as a sealing material between the opposing semiconductor chips 1 and between the semiconductor chips 1 and the interposer 5.

In a bump forming method with a high degree of freedom such as area bump chip technology, the semiconductor chip can be directly mounted on the motherboard without using an interposer. The curable adhesive layer according to the present embodiment can also be applied when such a semiconductor chip is directly mounted on a motherboard. The curable adhesive layer according to the present embodiment can also be applied when sealing or filling the gaps between the substrates when the two wiring circuit boards are laminated.

<Thermosetting resin composition>
The curable adhesive layer may be a layer containing a thermosetting resin having a molecular weight of 10,000 or less and a thermosetting resin composition containing the curing agent.

(A) Thermosetting resin A thermosetting resin is a compound capable of forming a crosslinked structure by heating. The thermosetting resin may have a molecular weight of 10,000 or less. Since the thermosetting resin composition contains a compound (thermosetting resin) that reacts with a curing agent to form a crosslinked structure, voids generated by decomposition of components having a small molecular weight during heating are suppressed. It is advantageous in terms of heat resistance. Examples of the thermosetting resin include epoxy resin and acrylic resin.

The weight average molecular weight of the thermosetting resin may be 100 to 9000 or 300 to 7000 from the viewpoint of heat resistance and fluidity. The method for measuring the weight average molecular weight of the thermosetting resin is the same as the method for measuring the weight average molecular weight of the polymer component (d) described later.

(A1) Epoxy resin An epoxy resin is a compound having two or more epoxy groups in the molecule. Examples of the epoxy resin include bisphenol A type, bisphenol F type, naphthalene type, phenol novolac type, cresol novolac type, phenol aralkyl type, biphenyl type, triphenylmethane type and dicyclopentadiene type epoxy resins, and various polyfunctional epoxys. Resin is mentioned. From the viewpoint of heat resistance and handleability, the epoxy resin may be selected from bisphenol F type, phenol novolac type, cresol novolac type, biphenyl type, and triphenylmethane type epoxy resin. From the viewpoint of quick curing and heat resistance, the epoxy resin may be selected from bisphenol F type and triphenylmethane type epoxy resins. The epoxy resin may be used alone or in combination of two or more.

The content of the epoxy resin may be 10 to 50 parts by mass with respect to 100 parts by mass of the total amount of the thermosetting resin composition. When the content of the epoxy resin is 10% by mass or more, the curing component is sufficiently present, so that it becomes easy to control the flow of the thermosetting resin composition after curing. When the content of the epoxy resin is 50% by mass or less, the warp of the package due to the cured product becoming too hard can be further suppressed.

(A2) Acrylic resin Acrylic resin is a compound having one or more (meth) acryloyl groups in the molecule. As the acrylic resin, for example, a skeleton derived from a compound selected from bisphenol A, bisphenol F, naphthalene, phenol novolac, cresol novolac, phenol aralkyl, biphenyl, triphenylmethane, dicyclopentadiene, fluorene, adamantan and isocyanuric acid and ( Examples include (meth) acrylates having a meta) acryloyloxy group and various polyfunctional (meth) acrylic compounds. From the viewpoint of heat resistance, the acrylic resin may be selected from (meth) acrylates having a skeleton derived from a compound selected from bisphenol A, bisphenol F, naphthalene, fluorene, adamantane and isocyanuric acid. As the acrylic resin, one type can be used alone or two or more types can be used in combination.

The content of the acrylic resin may be 10 to 50 parts by mass or 15 to 40 parts by mass with respect to 100 parts by mass of the total amount of the thermosetting resin composition. When the content of the acrylic resin is 10% by mass or more, the curing component is sufficiently present, so that it becomes easy to control the flow of the thermosetting resin composition after curing. When the content of the acrylic resin is 50% by mass or less, the warp of the package due to the cured product becoming too hard can be further suppressed.

The acrylic resin may be solid at room temperature (25 ° C.). The solid acrylic resin is advantageous over the liquid one in that voids are less likely to occur and that the thermosetting resin composition before curing (B stage) has a small viscosity (tack) and is excellent in handleability. Is. Examples of the acrylic resin that is solid at room temperature (25 ° C.) include (meth) acrylate having a skeleton derived from a compound selected from bisphenol A, fluorene, adamantane, and isocyanuric acid.

The number of (meth) acryloyl groups (number of functional groups) in the acrylic resin may be 3 or less. When the number of functional groups is 3 or less, the thermosetting resin composition can be sufficiently cured in a short time, so that a decrease in the curing reaction rate can be further suppressed. If the curing reaction rate is low, unreacted groups may remain.

(B) Curing agent The curing agent is a compound that reacts with a thermosetting resin to form a crosslinked structure together with the thermosetting resin. Examples of the curing agent include a phenol resin-based curing agent, an acid anhydride-based curing agent, an amine-based curing agent, an imidazole-based curing agent, a phosphine-based curing agent, an azo compound, and an organic peroxide. The curing reaction (curing system) may be radical polymerization (radical polymerization system). The curing agent may be used alone or in combination of two or more. The phenol resin-based curing agent, the acid anhydride-based curing agent, and the amine-based curing agent can be used alone or as a mixture of two or more. The imidazole-based curing agent and the phosphine-based curing agent may be used alone, or may be used together with a phenol resin-based curing agent, an acid anhydride-based curing agent, or an amine-based curing agent.

The combination of the thermosetting resin and the curing agent is not particularly limited as long as the curing progresses. From the viewpoint of excellent handling, storage stability and curability, the curing agent to be combined with the epoxy resin includes a phenol resin-based curing agent and an imidazole-based curing agent, an acid anhydride-based curing agent and an imidazole-based curing agent, and an amine-based curing agent. It may be selected from the imidazole-based curing agent and the imidazole-based curing agent alone. Since productivity is improved when curing is performed in a short time, an imidazole-based curing agent having excellent quick-curing property and storage stability may be used alone. When the thermosetting resin composition is cured in a short time, the amount of volatile components such as low molecular weight components can be reduced, so that the generation of voids can be further suppressed. The curing agent combined with the acrylic resin may be an organic peroxide or an azo compound from the viewpoint of handleability and storage stability. The curing agent to be combined with the acrylic resin may be an organic peroxide from the viewpoint of handleability and storage stability.

(B1) Phenol resin-based curing agent The phenol resin-based curing agent has two or more phenolic hydroxyl groups in the molecule. Examples of the phenol resin-based curing agent include phenol novolac, cresol novolac, phenol aralkyl resin, cresol naphthol formaldehyde polycondensate, triphenylmethane-type polyfunctional phenol, and various polyfunctional phenol resins. These can be used alone or in combination of two or more.

The equivalent ratio (phenolic hydroxyl group / epoxy group, molar ratio) of the phenol resin-based curing agent to the epoxy resin is 0.3 to 1.5, 0.4 to 0.4 from the viewpoint of excellent curability, adhesiveness and storage stability. It may be 1.0, or 0.5 to 1.0. When this equivalent ratio is 0.3 or more, the curability tends to be improved and the adhesive strength tends to be further improved. When this equivalent ratio is 1.5 or less, unreacted phenolic hydroxyl groups do not remain excessively, the water absorption rate is suppressed to a low level, and the insulation reliability tends to be further improved.

(B2) Acid anhydride-based curing agent Examples of the acid anhydride-based curing agent include methylcyclohexanetetracarboxylic dianhydride, trimellitic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic dianhydride and ethylene glycol bis. Anhydrotrimellitic is mentioned. These can be used alone or in combination of two or more.

The equivalent ratio of the acid anhydride-based curing agent to the epoxy resin (acid anhydride group / epoxy group, molar ratio) is 0.3 to 1.5, 0. From the viewpoint of excellent curability, adhesiveness and storage stability. It may be 4 to 1.0 or 0.5 to 1.0. When this equivalent ratio is 0.3 or more, the curability tends to be improved and the adhesive strength tends to be further improved. When this equivalent ratio is 1.5 or less, unreacted acid anhydride is unlikely to remain excessively, the water absorption rate is suppressed to a low level, and the insulation reliability tends to be further improved.

(B3) Amine-based curing agent Examples of the amine-based curing agent include dicyandiamide and dodecanediamine. These can be used alone or in combination of two or more.

The equivalent ratio of the amine-based curing agent to the epoxy resin (number of active hydrogens of amino group / epoxy group, molar ratio) is 0.3 to 1.5, 0, from the viewpoint of excellent curability, adhesiveness and storage stability. It may be 4 to 1.0 or 0.5 to 1.0. When this equivalent ratio is 0.3 or more, the curability tends to be improved and the adhesive strength tends to be further improved. When this equivalent ratio is 1.5 or less, unreacted amines are unlikely to remain excessively, so that insulation reliability tends to be improved.

(B4) Imidazole-based curing agent Examples of the imidazole-based curing agent include 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-. Cyanoethyl-2-undecylimidazole, 1-cyano-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole trimerite, 1-cyanoethyl-2-phenylimidazolium trimerite, 2,4-diamino-6 -[2'-methylimidazolyl- (1')]-ethyl-s-triazine, 2,4-diamino-6- [2'-undecylimidazolyl- (1')]-ethyl-s-triazine, 2, 4-Diamino-6- [2'-ethyl-4'-methylimidazolyl- (1')] -ethyl-s-triazine, 2,4-diamino-6- [2'-methylimidazolyl- (1')] -Ethyl-s-triazine isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, and epoxy resin And imidazoles adducts. From the viewpoint of excellent curability, storage stability and connection reliability, imidazole-based curing agents are used as 1-cyanoethyl-2-undecylimidazole, 1-cyano-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole tri. Meritate, 1-cyanoethyl-2-phenylimidazolium trimerite, 2,4-diamino-6- [2'-methylimidazolyl- (1')] -ethyl-s-triazine, 2,4-diamino-6 -[2'-Ethyl-4'-methylimidazolyl- (1')]-ethyl-s-triazine, 2,4-diamino-6- [2'-methylimidazolyl- (1')]-ethyl-s- You may choose from triazine isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole and 2-phenyl-4-methyl-5-hydroxymethylimidazole. These can be used alone or in combination of two or more. Further, these may be used as a microencapsulated latent curing agent.

The content of the imidazole-based curing agent may be 0.1 to 20 parts by mass or 0.1 to 10 parts by mass with respect to 100 parts by mass of the epoxy resin. When this content is 0.1 parts by mass or more, the curability tends to be improved. When this content is 20 parts by mass or less, the thermosetting resin composition is difficult to cure before the metal bond is formed, so that a connection failure tends to be difficult to occur.

(B5) Phosphine-based curing agent Examples of the phosphine-based curing agent include triphenylphosphine, tetraphenylphosphonium tetraphenylborate, tetraphenylphosphonium tetra (4-methylphenyl) borate and tetraphenylphosphonium (4-fluorophenyl) borate. Can be mentioned. These can be used alone or in combination of two or more.

The content of the phosphine-based curing agent may be 0.1 to 10 parts by mass or 0.1 to 5 parts by mass with respect to 100 parts by mass of the epoxy resin. When this content is 0.1 parts by mass or more, the curability tends to be improved. When this content is 10 parts by mass or less, the thermosetting resin composition is difficult to cure before the metal bond is formed, so that a connection failure tends to be difficult to occur.

(B6) Azo Compound Examples of the azo compound include dimethylaminoazobenzene, dimethylaminoazobenzene-carboxylic acid, diethylaminoazobenzene, and diethylaminoazobenzene-carboxylic acid. The azo compound may be used alone or in combination of two or more.

The content of the azo compound may be 0.5 to 10 parts by mass or 1 to 5 parts by mass with respect to 100 parts by mass of the acrylic resin. When this content is 0.5 parts by mass or more, the curability tends to be improved. If this content is 10 parts by mass or less, the thermosetting resin composition is unlikely to be cured before the metal bond is formed, so that connection failure tends to be difficult to occur.

(B7) Organic Peroxides Examples of organic peroxides include ketone peroxides, peroxyketals, hydroperoxides, dialkyl peroxides, diacyl peroxides, peroxydicarbonates, and peroxyesters. The organic peroxide may be one or more selected from hydroperoxide, dialkyl peroxide and peroxy ester from the viewpoint of storage stability. The organic peroxide may be one or more selected from hydroperoxide and dialkyl peroxide from the viewpoint of heat resistance. These can be used alone or in combination of two or more.

The content of the organic peroxide is preferably 0.5 to 10 parts by mass, more preferably 1 to 5 parts by mass with respect to 100 parts by mass of the acrylic resin. When this content is 0.5 parts by mass or more, the curability tends to be improved. If this content is 10 parts by mass or less, the thermosetting resin composition is unlikely to be cured before the metal bond is formed, so that connection failure tends to be difficult to occur. In addition, if this content is moderately low, the curing progresses rapidly and the number of reaction sites increases, resulting in a shortened molecular chain and residual unreacted groups, resulting in a decrease in reliability. It tends to be difficult to occur.

(C) Polymer component The thermosetting resin composition according to the present embodiment may further contain a polymer component having a weight average molecular weight of 10,000 or more. The weight average molecular weight or molecular weight of components other than the polymer component, such as thermosetting resins and curing agents, is usually less than 10,000. Examples of the polymer component include epoxy resin, phenoxy resin, polyimide resin, polyamide resin, polycarbodiimide resin, cyanate ester resin, acrylic resin, polyester resin, polyethylene resin, polyether sulfone resin, polyetherimide resin, and polyvinyl acetal resin. , Urethane resin and acrylic rubber. From the viewpoint of excellent heat resistance and film forming property, the high molecular weight component may be selected from epoxy resin, phenoxy resin, polyimide resin, acrylic resin, acrylic rubber, cyanate ester resin and polycarbodiimide resin. From the viewpoint of further excellent heat resistance and film forming property, the high molecular weight component may be selected from epoxy resin, phenoxy resin, polyimide resin, acrylic resin and acrylic rubber. These polymer components may be used alone or in combination of two or more.

The mass ratio of the polymer component and the epoxy resin is not particularly limited. The content of the epoxy resin may be 0.01 to 5 parts by mass, 0.05 to 4 parts by mass, or 0.1 to 3 parts by mass with respect to 1 part by mass of the polymer component. When this mass ratio is 0.01 parts by mass or more, the curability tends to be improved and the adhesive strength tends to be further improved. When this mass ratio is 5 parts by mass or less, the film-forming property and the film-forming property of the thermosetting resin composition tend to be particularly excellent.

The mass ratio of the polymer component and the acrylic resin is not particularly limited. The content of the acrylic resin may be 0.01 to 10 parts by mass, 0.05 to 5 parts by mass, or 0.1 to 5 parts by mass with respect to 1 part by mass of the polymer component. When this mass ratio is 0.01 parts by mass or more, the curability tends to be improved and the adhesive strength tends to be further improved. When this mass ratio is 10 parts by mass or less, the film-forming property of the thermosetting resin composition tends to be particularly excellent.

The glass transition temperature (Tg) of the polymer component may be 120 ° C. or lower, 100 ° C. or lower, or 85 ° C. or lower from the viewpoint of excellent adhesion of the thermosetting resin composition to the substrate and the chip. The Tg of the high molecular weight component may be 0 ° C. or higher. When the Tg of the polymer component is 120 ° C. or lower, it becomes easy to embed the height difference of the bumps formed on the semiconductor chip, the electrodes formed on the substrate, the wiring pattern, etc. in the thermosetting resin composition, so that bubbles remain. Is suppressed and voids tend to be less likely to occur. In the present specification, Tg is determined by differential scanning calorimetry under the conditions of a sample amount of 10 mg, a heating rate of 10 ° C./min, and a measurement atmosphere: air using a DSC (DSC-7 type manufactured by PerkinElmer Co., Ltd.). Means a value.

The weight average molecular weight of the polymer component may be 10,000 or more in terms of polystyrene, but may be 30,000 or more, 40,000 or more, or 50,000 or more in order to exhibit better film forming property by itself. In the present specification, the weight average molecular weight means a polystyrene-equivalent weight average molecular weight measured by high performance liquid chromatography (C-R4A manufactured by Shimadzu Corporation).

(D) Flux Agent The thermosetting resin composition according to the present embodiment may further contain a flux agent (that is, a flux activator exhibiting flux activity (activity to remove oxides and impurities)). Examples of the flux agent include nitrogen-containing compounds having unshared electron pairs such as imidazoles and amines, carboxylic acids, phenols and alcohols. Compared with alcohols and the like, organic acids (carboxylic acids such as 2-methylglutaric acid) strongly express flux activity, and connectivity and stability can be further improved.

The content of the flux agent may be 0.005 to 10.0% by mass based on the entire solid content (components other than the solvent) of the thermosetting resin composition.

(E) Filler The thermosetting resin composition according to the present embodiment generates voids and absorbs moisture in order to control the viscosity and physical characteristics of the cured product, and when semiconductor chips are connected to each other or a semiconductor chip and a substrate are connected to each other. Further fillers may be included for further control of the rate. Examples of the filler include an inorganic filler and a resin filler. Examples of the inorganic filler include insulating inorganic fillers such as glass, silica, alumina, titanium oxide, carbon black, mica and boron nitride. From the viewpoint of handleability, the inorganic filler may be selected from silica, alumina, titanium oxide and boron nitride, and from the viewpoint of shape uniformity (handleability), the inorganic filler may be selected from silica, alumina and boron nitride. May be good. The insulating inorganic filler may be a whiskers. Examples of whiskers include aluminum borate, aluminum titanate, zinc oxide, calcium silicate, magnesium sulfate and boron nitride. Examples of the resin filler include polyurethane, polyimide, methyl methacrylate resin and methyl methacrylate-butadiene-styrene copolymer resin (MBS). The filler may be used alone or in combination of two or more. The shape, particle size, and content of the filler are not particularly limited.

From the viewpoint of excellent insulation reliability, the filler may be insulating. The thermosetting resin composition according to the present embodiment may not substantially contain a conductive metal filler such as a silver filler or a solder filler. For example, the content of the conductive metal filler may be less than 1% by mass based on the entire solid content (components other than the solvent) of the thermosetting resin composition.

The physical properties of the filler may be appropriately adjusted by surface treatment. The filler may be a surface-treated filler from the viewpoint of improving dispersibility and adhesive strength. Examples of the surface treatment agent include glycidyl-based (epoxy-based), amine-based, phenyl-based, phenylamino-based, (meth) acrylic-based, and vinyl-based compounds.

As the surface treatment, silane treatment with a silane compound such as an epoxy silane type, an amino silane type, or an acrylic silane type is preferable because of the ease of surface treatment. The surface treatment agent may be a compound selected from glycidyl-based, phenylamino-based, acrylic-based and methacrylic-based compounds from the viewpoint of excellent dispersibility, fluidity and adhesive strength. From the viewpoint of storage stability, the surface treatment agent may be a compound selected from phenyl-based, acrylic-based and methacrylic-based compounds.

The average particle size of the filler may be 1.5 μm or less from the viewpoint of preventing biting when the flip chip is connected. The average particle size of the filler may be 1.0 μm or less from the viewpoint of excellent visibility (transparency). The particle size of the filler means the major axis diameter of the particles.

Compared with the inorganic filler, the resin filler can impart flexibility at a high temperature such as 260 ° C., and is therefore suitable for improving the reflow resistance. Further, since the resin filler can impart flexibility, it also contributes to improving the film formability of the thermosetting resin composition.

The content of the filler may be 30 to 90% by mass or 40 to 80% by mass based on the entire solid content (components other than the solvent) of the thermosetting resin composition. When this content is 30% by mass or more, the heat dissipation of the thermosetting resin composition becomes high, and the generation of voids and the hygroscopicity can be further suppressed. When this content is 90% by mass or less, it is possible to suppress a decrease in fluidity of the thermosetting resin composition due to an increase in viscosity and trapping of the filler in the connection portion, so that the connection reliability is improved. It tends to improve further.

で表されるシラノール化合物を更に含有していてもよい。式中、Ｒ^１はアルキル基、フェニル基又はこれらの組み合わせからなる基を示し、Ｒ^２はアルキレン基を示す。 (F) Silanol compound The thermosetting resin composition according to the present embodiment has (f) the following general formula (1):

It may further contain a silanol compound represented by. In the formula, R ¹ represents an alkyl group, a phenyl group or a group consisting of a combination thereof, and R ² represents an alkylene group.

The silanol compound represented by the general formula (1) may be solid at 25 ° C. from the viewpoint of heat resistance. ^{R 1} in the formula (1) may be an alkyl group or a phenyl group from the viewpoint of heat resistance and fluidity. R ¹ may be a group consisting of a combination of an alkyl group and a phenyl group (alkyl-substituted phenyl group or phenylalkyl group). Examples of the group represented by R ¹ include a phenyl group, a propyl group, a phenylpropyl group, and a phenylmethyl group. ^{R 2} in the formula (1) is not particularly limited, but may be an alkylene group having a weight average molecular weight of 100 to 5000 from the viewpoint of heat resistance. A ^{silanol compound in which R 2} is an alkylene group having a weight average molecular weight of 100 to 5000 usually has a weight average molecular weight in the range of about 100 to 5000. From the viewpoint of high reactivity (cured product strength), the silanol compound may be trifunctional silanol.

By adding the (f) silanol compound to the thermosetting resin composition, the fluidity is improved, and the void suppression property and the high connectivity are further improved. When the fluidity is improved (the viscosity is lowered), it becomes easier to eliminate the voids caught during the tip contact. (F) The silanol compound has high heat resistance and its thermal weight loss is small. By using a silanol compound having high heat resistance, the generation of voids can be further suppressed. When the amount of thermogravimetric reduction is small, the amount of volatile matter is small, so that voids are reduced and reliability (reflo resistance) is further improved.

(F) The content of the silanol compound may be 2 to 20% by mass based on the total amount of solids (components other than the solvent) of the thermosetting resin composition, and has high fluidization and cured product strength (adhesion). From the viewpoint of force, etc.), it may be 2 to 10% by mass, or 2 to 9% by mass. When this content is 2% by mass or more, a more remarkable effect is likely to be exhibited in terms of high fluidization. When this content is 20% by mass or less, the strength after curing tends to increase and a particularly high adhesive force tends to be exhibited. (F) When the content of the silanol compound is small to some extent, the ratio of the cured product of the epoxy resin or the acrylic resin is large, and it is presumed that higher adhesive strength is exhibited.

The thermosetting resin composition according to the present embodiment may further contain additives such as an ion trapper, an antioxidant, a silane coupling agent, a titanium coupling agent, and a leveling agent. As the additive, one type can be used alone or two or more types can be used in combination. The content of the additive may be appropriately adjusted so that the effect of each additive is exhibited.

The thermosetting resin composition according to this embodiment can be used for pressure bonding at a high temperature of 200 ° C. or higher. Further, in a flip chip package in which a metal such as solder is melted to form a connection, further excellent curability is exhibited.

The curable adhesive layer according to the present embodiment may be a layer formed of a film-like adhesive from the viewpoint of improving productivity. An example of a method for producing a film-like adhesive is shown below.

First, if necessary, a thermosetting resin, a curing agent, a polymer component, a filler, other additives, etc. are added to an organic solvent and then dissolved or dispersed by stirring and mixing, kneading, etc. to prepare a resin varnish. To do. Next, a resin varnish is applied to the release-treated base film using a knife coater, a roll coater, an applicator, a die coater, a comma coater, or the like, and then the organic solvent is reduced by heating to reduce the base film. A film-like adhesive is formed on the film. Before reducing the amount of organic solvent by heating, a resin varnish may be spin-coated on a wafer or the like to form a film, and then a film-like adhesive may be formed on the wafer by a method of solvent drying.

The base film is not particularly limited as long as it has heat resistance that can withstand the heating conditions when the organic solvent is volatilized, and is a polyester film, a polypropylene film, a polyethylene terephthalate film, a polyimide film, a polyetherimide film, or a poly. Examples thereof include ether naphthalate film and methylpentene film. The base film is not limited to a single-layer film composed of one of these films, and may be a multilayer film composed of two or more types of films.

The heating conditions for volatilizing the organic solvent from the resin varnish after coating may be, for example, in the range of 50 to 200 ° C. for 0.1 to 90 minutes. If there is no effect on the void and viscosity adjustment after mounting, the heating condition may be a condition in which the organic solvent volatilizes to 1.5% or less.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following examples.

The compounds used in the examples are shown below.
(A) Thermosetting Resin Epoxy Resin / Triphenol Methane Skeleton-Containing Polyfunctional Solid Epoxy Resin (EP1032H60, manufactured by Mitsubishi Chemical Corporation, weight average molecular weight: 800 to 2000)
-Bisphenol F type liquid epoxy resin (YL983U, manufactured by Mitsubishi Chemical Corporation, molecular weight: about 336)
-Flexible semi-solid epoxy resin (YL7175-1000, manufactured by Mitsubishi Chemical Corporation, weight average molecular weight: 1000 to 5000)

(B) Hardener ・ 2,4-diamino-6- [2'-methylimidazolyl- (1')] -ethyl-s-triazine isocyanuric acid adduct (2MAOK-PW, manufactured by Shikoku Chemicals Corporation)

(C) Polymer component / phenoxy resin (ZX1356-2, manufactured by Toto Kasei Co., Ltd., Tg: about 71 ° C., weight average molecular weight: about 63000)

(D) Flux agent, 2-methylglutaric acid (manufactured by Aldrich, melting point: about 77 ° C)

(E) Filler Resin filler / organic filler (EXL-2655, manufactured by Rohm and Haas Japan Co., Ltd., core-shell type organic fine particles)
Inorganic filler / silica filler (SE2050, manufactured by Admatex Co., Ltd., average particle size: 0.5 μm)
-Phenyl surface-treated nanosilica filler (YA050C-SP, manufactured by Admatex Co., Ltd., average particle size: about 50 nm)

・固形シラノール、Ｒ^１：フェニル基、Ｒ^２：アルキレン基、Ｘ：Ｈ（ＦＣＡ１０７、東レダウコーニング株式会社製、分子量：約３０００） (F) Silanol compound A silanol compound represented by the following chemical formula was prepared.

-Solid silanol, R ¹ : phenyl group, R ² : alkylene group, X: H (FCA107, manufactured by Toray Dow Corning Co., Ltd., molecular weight: about 3000)

(Method for producing thermosetting resin composition)
Various raw materials were mixed at the blending ratios shown in Table 1 to prepare a thermosetting resin composition A. The specific production method is shown below. Thermosetting resins (EP1032H60, YL983U, and YL7175-1000), curing agents (2MAOK-PW), flux agents (2-methylglutaric acid), fillers (EXL-2655, SE2050, and YA050C-SP), and silanol compounds. (FCA107) was added to methyl ethyl ketone so that the non-volatile content (solid content) concentration was 60% by mass. Then, beads having a diameter of 1.0 mm and a diameter of 2.0 mm were added to the mixed solution in the same mass as the solid content, and the mixture was stirred with a bead mill (planetary pulverizer P-7, manufactured by Fritsch Japan Co., Ltd.) for 30 minutes. A polymer component (ZX1356-2) was added to the mixture, and the mixture was stirred with a bead mill for 30 minutes. The beads were removed by filtering the mixed solution, and the filtrate was obtained as a thermosetting resin composition A.

(Method of producing film-like adhesive)
The produced thermosetting resin composition A is coated with a small precision coating device (manufactured by Yasui Seiki Co., Ltd.) to form a coating film, and the coating film is dried in a clean oven (manufactured by Espec Co., Ltd.) (70 ° C.). / 10 minutes) to obtain a film-like adhesive.

(Manufacturing method of semiconductor device)
(Example 1)
A film-like adhesive having a size of 7.3 mm × 7.3 mm × 0.045 mm ^t is applied to a semiconductor chip α with solder bumps (chip size: 7.3 mm × 7.3 mm × 0.15 mm ^t , bump height: copper). It was attached to a pillar + solder height meter of about 45 μm, number of bumps: 1048 pins, pitch: 80 μm, WALTS-TEG CC80ModelI, manufactured by WALTS). The metal material forming the surface of the connection portion of the semiconductor chip α is solder (Sn-Ag). This semiconductor chip with a film-like adhesive is brought into contact with the semiconductor chip β (chip size: 10 mm × 10 mm × 0.1 mm ^t , WALTS-TEG IP80, manufactured by WALTS) via the film-like adhesive, and the pressing member is pressed. (FCB3, manufactured by Panasonic Factory Solutions Co., Ltd.) was crimped (crimping process) to obtain a laminate. The connection portion of the semiconductor chip β is composed of Cu and Ni-Au laminated on the surface of Cu. The metal material forming the surface of the connection portion of the semiconductor chip β is Ni-Au. In the crimping process, the temperature of the stage of the pressing member is set to 80 ° C., the temperature of the crimping head of the pressing member is set to 130 ° C., and the semiconductor chip α and the semiconductor chip are heated and pressurized at a pressure of 100 N for 3 seconds. It was crimped with β. Subsequently, the laminate was transferred to a reflow furnace (manufactured by Tamura Corporation), heated at 170 ° C. for 90 seconds, and then continuously heated at 190 ° C. for 90 seconds to allow the curing reaction of the film-like adhesive to proceed. (Curing process). Then, the semiconductor chips were electrically connected to each other by heating the laminate at 260 ° C. for 90 seconds in the same reflow furnace continuously in the curing step (connection step) to obtain the semiconductor device of Example 1. In the connection process, the solder (Sn-Ag) at the connection portion of the semiconductor chip α melts, Ni-Au diffuses at the connection portion of the semiconductor chip β to expose Cu, and a metal bond of Sn-Ag-Cu is formed. Was done.

(Examples 2 and 3, Comparative Examples 1 and 2)
The semiconductor devices of Examples 2 and 3 and Comparative Examples 1 and 2 were manufactured in the same manner as in Example 1 except that the heating conditions of the curing step and the connecting step were changed as shown in Table 2. In Table 2, “X ₁ ° C. Y ₁ s → X ₂ ° C. Y ₂ s” (X ₁ , X ₂ , Y ₁ and Y ₂ represent numerical values, respectively. S represents seconds. The description of) means that after heating _{Y 1 s at X 1} ° C, it was subsequently heated _{Y 2 s at X 2} ° C.

Table 2 shows the heating conditions of the crimping step, the curing step, and the connecting step in the above Examples and Comparative Examples, and the melting points of the metal materials forming the surfaces of the connecting portions of the semiconductor chips α and β.

<Various measurements>
(Measurement of melt viscosity)
With respect to the thermosetting resin composition A, the melt viscosity at the temperature during the crimping step was measured by the following method using a rheometer (MCR301, manufactured by Anton Paar Japan K.K.). The thermosetting resin composition A was supplied onto the stage, and a measuring jig was installed so that voids did not enter. The measurement conditions are the distance between the stage and the measuring jig (φ8 mm) 0.3 mm, swing angle gamma = 5%, frequency f = 1 Hz, normal force FN = 0 μN, heating rate 10 ° C / min, measurement range 30 ° C to 180. The temperature was adjusted to ° C. The melt viscosity at 130 ° C. (temperature during the crimping process) was determined from the viscosity curve. The melt viscosity of the thermosetting resin composition A at 130 ° C. was 4200 Pa · s.

(Measurement of curing reaction rate)
With respect to the produced film-like adhesive, the curing reaction rate after heating under the same conditions as in the curing step was measured by the following method using DSC (DSC-7 type manufactured by PerkinElmer Co., Ltd.). First, 10 mg of the untreated film-like adhesive was placed in an aluminum pan, and differential scanning calorimetry was performed at a temperature rise rate of 20 ° C./min and a temperature range of 30 to 300 ° C., and the calorific value ΔH1 (J / g) due to the curing reaction was measured. ) Was asked. Subsequently, the untreated film-like adhesive was heated on a hot plate to obtain a heat-treated film-like adhesive. The heat treatment was carried out under the heating conditions of the curing step shown in Table 2. 10 mg of the film-like adhesive after this heat treatment was placed in an aluminum pan, and differential scanning calorimetry was performed at a temperature rise rate of 20 ° C./min and a temperature range of 30 to 300 ° C., and the calorific value ΔH2 (J / g) due to the curing reaction was measured. Asked. The curing reaction rate was calculated based on the following formula. The results are shown in Table 2 when the curing reaction rate is 80% or more as “≧ 80%” and when it is lower than 80% as “<80%”.
Curing reaction rate (%) = (ΔH1-ΔH2) / ΔH1 × 100

(Void evaluation)
An external image of the laminated body was taken after the connection step using an ultrasonic image diagnostic apparatus (Insight-300, manufactured by Insight Co., Ltd.). The image of the curable adhesive layer was captured by a scanner (GT-9300UF, manufactured by Seiko Epson Corporation). Using the image processing software Adobe Photoshop (registered trademark), the void portion was identified by color tone correction and bigradation. From the histogram, the ratio (%) of the area of the void portion to the area (100%) of the curable adhesive layer was calculated as the void generation rate. The case where the void occurrence rate was 5% or less was evaluated as "A", and the case where the void occurrence rate was higher than 5% was evaluated as "B". The results are shown in Table 2.

(Connection evaluation)
Using a multimeter (R6781E, manufactured by Advantest Co., Ltd.), the possibility of initial continuity of the semiconductor device was measured. When the initial connection resistance value of the inner circumference of the peripheral part was 32.0 to 38.0Ω, it was evaluated as "A" (good connection), and when it was other resistance value or not connected, it was evaluated as "B" (bad connection). .. The results are shown in Table 2.

(Evaluation of reflow resistance)
The semiconductor device is molded using a sealing material (CEL9750ZHF10, manufactured by Hitachi Kasei Co., Ltd.) (conditions: 180 ° C./6.75 MPa / 90s) and aftercured at 175 ° C. for 5 hours in a clean oven (manufactured by ESPEC). It was. Subsequently, a high-temperature moisture absorption treatment was performed under the conditions of JEDEC level 2, and the mixture was passed through a reflow furnace (manufactured by Tamura Corporation) three times. The presence or absence of peeling in the semiconductor device was confirmed. Then, the connection evaluation of the semiconductor device was performed by the same method as described above. The case where there was no peeling and the connection was good was evaluated as "A", and the case where peeling or poor connection occurred was evaluated as B. The results are shown in Table 2.

As is clear from the results in Table 2, according to the method according to the present embodiment, it is possible to sufficiently suppress the generation of voids, obtain a semiconductor device having a good connection and excellent reflow resistance. it can.

1 ... Semiconductor chip, 2 ... Substrate, 3 ... Laminated body, 5 ... Interposer, 10 ... Semiconductor chip body, 15, 16 ... Wiring, 20 ... Board body, 30, 32, 33 ... Bump, 34 ... Through electrode, 40 ... Curable adhesive layer, 41 ... Crimping head, 42 ... Stage, 43 ... Pressing device, 50 ... Interposer body, 60 ... Heating furnace, 100, 200, 300, 400, 500 ... Semiconductor device.

Claims (7)

A semiconductor chip, a substrate or another semiconductor chip, and a curable adhesive layer interposed between them are provided, and each of the semiconductor chip, the substrate, and the other semiconductor chip has a connection portion, and the semiconductor chip, the substrate, and the other semiconductor chip each have a connection portion. Manufactures a semiconductor device in which at least a part of a connection portion is formed of a metal material, and the connection portion of the semiconductor chip is electrically connected to the substrate or the connection portion of the other semiconductor chip by metal bonding. How to do
It has the semiconductor chip, a semiconductor wafer including the substrate, the other semiconductor chip, or a portion corresponding to the other semiconductor chip, and the curable adhesive layer arranged between them. The laminate in which the connection portion of the semiconductor chip and the connection portion of the substrate or the other semiconductor chip are arranged to face each other is heated and pressurized by sandwiching the laminate between a pair of pressing members facing each other, thereby forming the semiconductor chip. A step of crimping the substrate, the other semiconductor chip, or the semiconductor wafer so that the connection portion of the semiconductor chip and the connection portion of the substrate or the other semiconductor chip are in contact with each other.
The step of advancing the curing reaction of the curable adhesive layer and
A step of electrically connecting the connection portion of the semiconductor chip and the connection portion of the substrate or the other semiconductor chip by metal bonding, and
In this order,
When at least one of the pair of pressing members heats and pressurizes the laminate, it determines the melting point of the metal material forming the connection portion of the semiconductor chip and the connection portion of the substrate or the other semiconductor chip. Heated to a temperature lower than the melting point of the forming metal material,
In the step of advancing the curing reaction of the curable adhesive layer, the melting point of the metal material in which the laminate forms the connection portion of the semiconductor chip in the heating furnace, and the substrate or the other semiconductor chip. It is heated to a temperature lower than the melting point of the metal material forming the connection portion, whereby the curing reaction of the curable adhesive layer proceeds until the curing reaction rate of the curable adhesive layer reaches 80% or more. Let me
In the step of electrically connecting the connection portion of the semiconductor chip and the connection portion of the substrate or the other semiconductor chip by metal bonding, the laminate is a metal material forming the connection portion of the semiconductor chip. It is heated to a temperature equal to or higher than the melting point or the melting point of at least one of the metal materials forming the connection portion of the substrate or the other semiconductor chip.
Method. The method according to claim 1, wherein the melt viscosity of the curable adhesive layer is 10,000 Pa · s or less at a temperature at which the pressing member is heated. The method according to claim 1 or 2, wherein the curable adhesive layer is a layer containing a thermosetting resin having a molecular weight of 10,000 or less and a thermosetting resin composition containing the curing agent. The method according to claim 3, wherein the thermosetting resin composition further contains a polymer component having a weight average molecular weight of 10,000 or more. The method according to claim 4, wherein the weight average molecular weight of the polymer component is 30,000 or more, and the glass transition temperature of the polymer component is 100 ° C. or less. The method according to any one of claims 1 to 5, wherein the curable adhesive layer is a layer formed of a film-like adhesive. The method according to any one of claims 1 to 6, wherein the pressure in the heating furnace is atmospheric pressure.

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